Bosch BSA 250 Betriebsanleitung Seite 38

Figure 3 shows the roller sets (8).
10 11
16 15
Figure 3, roller sets
9. Centre cover plate
10. LH cover panel
11. LH test rollers
12. RH test rollers
13. RH cover panel
14. RH sensing roller
15. Mounting screws
16. LH sensing roller
If the system is installed in a normal pit, it is
essential that the centre cover plate is atta-
ched, otherwise there is a danger that either a
person or vehicle could fall into the pit. Injury
hazard!
Underneath the sensing rollers there is a tread guard which
prevents feet from become trapped.
38
6.
This brake system analyser is intended to be used for testing
12 13
vehicle brake systems.
In order to test the brake system, the vehicle must be driven onto
the stand so that the wheels of the axle to be tested are positioned
on top of the rollers (8).
Figure 4 shows a sectional view of the left-hand roller set.
453256/3P
9 14
Figure 4:
23. Wheel to be tested
24. Chain for driving rollers
The right-hand and left-hand brakes are tested independently of
each other.
The tester can test the brakes on all axles without leaving the
vehicle.
The drive motors for the rollers (8) can be switched on either via
the remote control (special accessory) or automatically. When
the vehicle is driven onto the rollers, the sensing rollers (14,16)
are pressed down which automatically switches on the roller drive
motors. When the vehicle is driven off the stand, the sensing
rollers (14,16) move upwards again which causes the drive
motors to switch off automatically.
The test rollers (11,12) have a special coating. Due to the very
high coefficient of friction, the amount of brake force that is
transferred is very high, even if the axle load is relatively low.
When the brake force becomes greater than the friction force
between the wheel (23) and the test rollers (11,12), the wheel
begins to slip (lock up). When this happens, it is no longer the
braking force that is measured but solely the resistance to slip
between the wheel (23) and the test rollers (11,12). This
measurement is meaningless for the brake test. The automatic
slip disable function prevents this type of measurement error as
well as any damage to the tyres. The amount of slip is determined
by measuring the rotational speed via the sensing rollers (14,16).
When the maximum permissible slip value is exceeded, the drive
motors switch off. Once the slip disable function (cut-out) has
been activated, the brake force level reached is displayed. You
may find that the brake force indication continues to rise after the
slip disable function has activated, especially if you increase the
brake force rapidly. The decisive value for evaluation of the
maximum braking ratio is the maximum value indicated for the
brake force.
The measured values are transferred to the computer for
evaluation. Test reports can be printed out.
Functional description
(14,16)
(11,12)
22.01.03
23
24
453257/3P
(11,12)
1 689 979 689